1. Field of the Invention
The invention relates to control valves for fluid motors or the like, and more particularly to control valve systems which may be arranged in various ways to perform different functions, as a result of the varied choice of pilot valves and main valve parts. The invention is particularly pertinent to systems using poppet valves rather than spool valves, such systems being especially useful in industrial environments such as foundries where the dust laden atmosphere could cause spool valves to become clogged.
2. Description of the Prior Art
Generally speaking, it has been necessary in the past to design a particular poppet valve system to accomplish a given function, and this system is thereafter incapable of being easily converted to another use. For example, if a specific arrangement of pilot operated main poppet valves is designed to achieve a two position four-way function in the control of opposite ends of a reciprocable fluid motor, it is difficult if not impossible to change such a construction to achieve another function, such as the independent or sequential operation of two, three or four separate fluid motors.
An example of a four-way poppet valve in the prior art which is constructed to achieve a specific function is shown in Stumpf U.S. Pat. No. 2,218,861. This patent, however, has drawbacks as compared with the present invention which will hereinafter appear.